Coupling device



1941- J. s. DONALDSON 2,260,215

COUPLING DEVICE Filed March 25, 1940 14 IVENTOR MMWm MATTQR EY Patented Oct. 21, 1941 I UNITED STATE S PATENT OFFICE This invention relates to a locking device for preventing a hook from becoming disconnected from a chain link, ring, rod or the like. The object of the invention is to provide hooks with locking means which shall be effective for preventing accidental disconnection of the hook, while at the same time the hook may be readily attached to or disconnected from the link or the like without the use of any tool. The invention has been made especially with the idea of its application to the hooks of anti-skid chains for wheel tires the cross-chains of which are customarily connected to the side chains by means of hooks, the hook ends of which after connection are bent down to prevent the hooks from becoming disconnected. When these crosschains through wear break in two the chain pieces have to be removed and new cross-chains substituted. The bent hooks can be disconnec'ted. from the side chains only with the use of tools intended for that purpose, and then only with difficulty and considerable inconvenience. Use of the locking device of the present invention avoids all need of bending the hook ends, and makes it possible to quickly and easily disconnect broken cross-chains by hand and to quickly and easily attach new cross-chains by hand, avoiding entirely the use ofany tool. An additional advantage is that instead of the hooks being semi-hard so that the ends may be bent for locking and unlocking the hooks, they may be fully hardened to the point of their greatest resistance to bending or breaking, thus greatly increasing the resistance of the hooks to deformation in use.

While the invention will be illustrated and particularly described as applied to tire chains, it is to be understood that it is also suitable for and intended for other uses.

In the accompanying drawing- Fig. 1 is a plan View of a tire chain hook provided with a locking device according to the invention, the hook being connected at its loop end to the end link of a cross-chain and at its hook end to a link of a side chain;

Fig. 2 is a side view of the parts shown in Fig. 1 with the side chain link to which the hook is connected shown in section;

Fig. 3 is an end view of the hook and locking device looking from the left of Fig. 1; and

Figs. 4, 5 and 6 are views similar to Figs. 1, 2 and 3, respectively, except that they show a hook of slightly different form and the locking device as of modified form to suit the hook.

Referring to the drawing, and first to Figs. 1,

2 and 3, the hook 3 as shown in these figures is of a well-known form used for tire chains made of strong wire or light rod stock bent to form twin prongs or hook ends 4 extending from a looped shank, the diameter or spread of the loop of which is substantially greater than the spacing of the two hook ends so that the sides of the shank diverge toward the loop end to the width of the loop. The loop being open, the hook can be threaded into an end link 5 of the cross-chain, and the cross-chain is connected to the side chain by hooking the hook ends of the hook into one of the links 6 of the side chain.

' The" locking device Hlcomprises a part II for attachment to the shank of the hook and. a forwardly extending spring finger l2 having a part 13 which extends at right angles, or approximately so, to the shank of the hook and serves when in its normal position as an abutment closing the hook opening. When the hook is an open-loop twin-prong hook, the locking device is most desirably made to be detachably attached thereto so as to avoid interference with the threading of the hook into the cross-chain link or removing it therefrom, which would result from having the locking device permanently attached to the sides of the shank of the hook. The part H of a detachable locking device for use with a hook of the shape shown in Figs. 1 to 3 is made as a cross-piece having flanged ends l4 curved to pass partly around and fit the diverging sides, of the shank of the hook, andv the abutment part 13 of the spring finger 12 extends between the hook ends, closing the hook opening when in normal position as shown in Fig. 2, extending most desirably entirely across the opening as shown.

After the hookhas been threaded into the end link 5 of the cross-chain; the locking device is attached to the hook by sliding its cross-piece ll along on the shank of the hook until its flanged ends M are firmly seated on the diverging sides of the shank. The cross-chain may then be connected to the side chain by pressing 5 the side of the side chain link 6 against the spring finger I2 so as to flex it downward, thereby moving the abutment l3 downward to open the hook opening sufficiently to permit the side of the link to pass, and then by relative movement of the hook and link causing the side of the link to enter to the position shown in the figures. The abutment, after the side of the link has passed it, returns to its normal position shown in Fig. 2, thereby closing the hook opening and thereafter serves to prevent accidental end links of a new cross-chain.

. withieach other.

.ingdevice is, therefore, made shorter than in the disconnection of the hook from the link. To disconnect the hook from the side chain link when desired it is only necessary to depress the spring finger so as to permit the side of the link to pass between the abutment and the hook ends out of the hook opening.

The pieces of a broken cross-chain may thus be easily removed without the use of any tool, and then, after detaching the locking devices from the hooks, the. hooks may be disconnected from the cross-chain pieces and threaded into the Fromthe lower end of the abutment I3 a stop,

piece I5 extends between the hook ends. .This

stop piece serves to prevent the side ofli'nk B from passing beneath the abutment if the spring finger should be pushed upward, and, by engagelocking. device having a part attached to the shank ment with the the when the chain is in use, t prevent the spring finger from being pushed downward sufliciently to permit the link side from escapin past the, upper end of the abutment.

.,.'Fi$.-1', 5 and 6,.sjhow the locking device [0' of a, slightly modified, fonm adapted for and as applied to 3 a different 'form of twin-prong hook .whichis also in common use for tire chains, this hook 3jpdiffering from'the hook of Figs." 1 to 3 .onlyin that the two :sides of theshank of the v hook extend straight from the hook ends parallel The cross-piece I I of the lockformof the device shown in Figs. 1, 2 and 3, and its flanged ends M are shaped to fit with a sliding fit about the parallel side pieces of the shank; and. in'attaching thelocking device to the hook, the; crossepiece is threaded over the hook ends and then slid along on the shank of the hook to r the position shown in Figs. 4 and 5. The spring finger J2 has extending upward from its stop piece 15 an'end piece 16 which is parallel, or approximately so, tothe abutment 1'3 and spaced therefrom sothat it will extend between the .two sides of the link 6 to which the hook is connectedend extension [6 of the spring finger thus :serves by engagement with the sideof the link to limit backward movement of the'spr-in'g finger andv its sliding cross-piece I l on the shank of the hook, thereby'preventing the abutment l3 from beingmoved so far backward'as to permit the 'linkis'ide from escaping from the hook opening, and forward movement of the locking de vice is limited by engagement of the abutment with the side of the link. As the device fora straight shank hooksho wn in th'ese'fi'gures has to be attached to the hook by threading its cross member over the hook ends, the flanged ends I4 may be extended and welded or otherwise secured together if desired for increasing the strength of the attaching part.

locking device having a part detachably attachedto the shank of the hook and a forwardly extending spring finger shaped to provide at its forward end between the hook ends an abutment which 7 in its normal position closes the hook opening and which has a stop piece extending from its lower end.

2. A coupling, comprising a hook having twin hook ends extending from a looped shank, and a of the hook and a forwardly extending spring finger" shaped to provide at its forward end between the hook ends an abutment which in its normal position closes the hook opening and.

Which has end. H

.3. A coupling, comprising a hook having twin hook ends extending from a looped shank the sides of which diverge toward the loop end; and a detachable locking device comprising a crosspiece having flanged ends formed to fit the diverging sides of the shank, a forwardly extenda stop piece extending from its lower ing spring finger shaped to provide at itsforward end between the hook ends an abutment which in its normal position closes the hook open- .ing and which has, a stop piece extending from its lower end., 7

4. A coupling, comprising a hook having twin hook ends extending from a looped shank having parallel sides; and a detachable locking device comprising a part formed to slide on the shank, and a forwardly extending spring finger shaped to provide at its forward end between the hook .ends" an abutment which in its normal position closes the hook opening and having extending from thelower end of the abutment a stop piece and from the outer end of the stop piece an upend piecespaced from the abut- 5. A locking device. for preventinga hook having twin hook ends extending .from a looped shank "from becoming unhooked from ta link or the like, comprising a part formed 'for detachable attachment 'to the shank .of the :hookand a .spring finger extending therefrom shaped to provide an abutment to lie between the hook ends and in its normal position to close the hook opening :and a stop piece extending from the abutment.

JOHN DONALDSOlV. j 

